In the design and manufacture of deodorant or antiperspirant stick products it is preferable that the top of the stick have a convex contour and that its cross-sectional shape be circular or oval. The convex shape is desired so that the product is comfortable to apply upon its first application and has a good appearance to the consumer. The oval cross-section makes the application more efficient by requiring a minimum number of strokes to apply the product evenly. Such packages are typically equipped with an elevator screw dispensing system wherein an elevator platform is disposed within the package at its bottom end and has a spindle in threaded engagement therewith. A hand wheel to turn the spindle is located outside the bottom of the package for use by the consumer in advancing and retracting the product.
One method of manufacturing such products is known as the bottom fill method. The desired shape of the stick product is generally achieved by providing a package having an oval or circular cross-section and a cap, factory seal or puck of the same cross-section on the top of the package. The cap/puck/seal has a smooth concave inner surface which is adapted to function as a mold in forming the top of the stick. The product is poured into the package in its molten state through the bottom. While the product is still in the molten or liquid form the elevator/screw system is inserted into the package and the bottom of the container is sealed. The product and package are then allowed to cool whereby the shape of the package and the cap cause the product to take on the desired appearance. An example of a cosmetic stick-type dispensing package especially adapted for use with the bottom fill manufacturing method can be found in U.S. Pat. No. 4,369,158 issued to Woodruff et al. on Jan. 18, 1983.
Another and more preferable method used to manufacture stick-type cosmetic products is known as the fill/invert method. This method produces a product with the desired shape by providing a package having an oval or circular cross-section but with a closed bottom. The package has the elevator/screw dispensing system disposed therein before filling. The product is poured into the package through the top and the top of the package is then sealed with a factory seal or a puck having a smooth concave inner surface for molding the end of the stick. The package is thereafter inverted so that some of the molten product flows from the bottom of the package to the top to fill the outage volume, which is the volume intermediate the original fill line and the factory seal or puck. The package is then kept in this position during cooling. An example of a package especially adapted for use with the fill/invert manufacturing process is described in co-pending and commonly assigned U.S. application Ser. No. 760,661 filed in the names of Dornbusch et al. on Sep. 16, 1991 the disclosure of which is hereby incorporated herein by reference.
Recently, there has been a desire to make a sample/trial size or limited use package for cosmetic stick form products. A limited use, sample size or trial size package is typically one that is designed for less than 25 applications of product. One method of of producing such packages is to make a smaller size version of either of the packages described above. However, the elevator/screw dispensing systems present in such packages make this impractical as it would cause the sample size package to have too many parts and, therefore, be too expensive. Because limited use sample or trial size packages are often made available to the consumer at little or no cost it is preferable to produce them relatively cheaply. Therefore, there has been a desire to make a low cost sample size package for a cosmetic stick form product that does not need an elevator screw dispensing system or any type of advancing means for the product within the package.
Cosmetic stick form packages have been made in the past that do not require an advancing means for the product within the package. An example of such a package is described in U.S. Pat. No. 4,728,210 issued to Barrish et al. oil Mar. 1, 1988. This reference discloses a solid personal care product that is packaged in a container having a cover and a handle. All of the product extends above the handle and the cap is big enough to cover all of the product when the package is not in use. Therefore, this package requires no advancing means. Another package similar to Barish et al. that requires no advancing means is described in U.S. Pat. No. 4,235,557 issued to Hayes on Nov. 25, 1980. However, both of the packages disclosed in the above mentioned references are bottom fill packages which require that the bottom of the package be sealed after filling. This procedure would add expense to a sample size product.
Furthermore, because the cosmetic products in such packages are often composed of a large proportion of volatile materials such as alcohol, it is necessary to seal the package thoroughly prior to use by consumers in order to prevent the escape of these materials during manufacture, shipment and storage. When the package is not effectively sealed, volatiles evaporate and the product shrinks losing its shape, fragrance and aesthetic appearance. The major problem of sealing the bottom fill packages has been to provide an effective sealing means on the bottom of the package after the package has been filled. In bottom fill packages, the bottom wall is not integral with the package but must be attached after filling. The base must be sealed to the side walls in order to prevent the escape of volatiles therefrom. Because the fill/invert packages have the bottom wall integral with the base of the package to provide better sealing, it is the preferred method for manufacturing cosmetic stick-form products.
It is therefore an object of the present invention to provide a low cost limited use package for a cosmetic stick form product that is adapted for use with the fill/invert process of manufacture.
It is another object of the present invention to provide such a package that requires no advancing means within the product in order to eliminate the costs associated therewith.
The aforementioned and other objects of the present invention will become more apparent hereinafter.